At 27, Daisy Johnson became the youngest ever author to be shortlisted for the Man Booker Prize last year for Everything Under, her eerie rewriting of the Oedipus myth – set in an insular houseboat community on the canals of Oxfordshire. Daisy has been lauded as “a new goddamn swaggering monster of fiction” by Fates and Furies author Lauren Groff. The British writer talks with Nadia Bailey about a novel that’s concerned with language, secrets and the damage wrought by what’s left unsaid.